Momentum exchange assemblies and inner gimbal assemblies for use in control moment gyroscopes

1. A momentum exchange assembly, comprising:

an outer housing; and

an inner gimbal assembly disposed within the outer housing, the inner gimbal assembly including:

a stator housing;

a rotor assembly disposed at least partially within the stator housing, the rotor assembly including a shaft and an inertial element fixedly coupled to the shaft;

a first spin bearing mounted to a first end of the shaft;

a bearing cartridge surrounding the first spin bearing, the bearing cartridge having a first end, a second end, and a bearing cartridge channel extending from the first end of the bearing cartridge to the second end of the bearing cartridge; and

a spin motor disposed within the stator housing and around the shaft, the spin motor including a spin motor rotor and a spin motor stator, the spin motor rotor coupled to the rotor assembly, and the spin motor stator disposed around a portion of the spin motor rotor and coupled to the stator housing,

wherein:

a first end cavity is partially defined by the first end of the bearing cartridge,

a first intermediary cavity is defined by a first portion of an outer surface of the spin motor, a first portion of a surface of the rotor assembly, and the second end of the bearing cartridge, and

the bearing cartridge channel provides flow communication between the first end cavity and the first intermediary cavity.

2. The momentum exchange assembly of claim 1 , further comprising:

a second spin bearing mounted to a second end of the shaft;

a diaphragm disposed around the second spin bearing; and

a diaphragm channel extending through the diaphragm.

3. The momentum exchange assembly of claim 1 , wherein the bearing cartridge comprises a plurality of bearing cartridge channels extending from the first end of the bearing cartridge to the second end of the bearing cartridge.

4. The momentum exchange assembly of claim 3 , wherein the plurality of bearing cartridge channels are substantially evenly spaced around the bearing cartridge.

5. The momentum exchange assembly of claim 1 , wherein:

the shaft includes a plurality of shaft channels extending through the shaft;

a second intermediary cavity is defined by a second portion of the outer surface of the spin motor and a second portion of the surface of the rotor assembly; and

the plurality of shaft channels provides flow communication between the first end cavity and the second intermediary cavity.

6. The momentum exchange assembly of claim 5 , wherein the plurality of shaft channels are substantially evenly spaced around the shaft.

7. The momentum exchange assembly of claim 1 , wherein:

the shaft includes a first shaft channel extending through the shaft;

a second intermediary cavity is defined by a second portion of the outer surface of the spin motor and a second portion of the surface of the rotor assembly; and

the first shaft channel provides flow communication between the first end cavity and the second intermediary cavity.

8. The momentum exchange assembly of claim 7 , wherein the first shaft channel curves from the first end cavity to the second intermediary cavity.

9. The momentum exchange assembly of claim 7 , wherein:

the first end of the shaft is disposed proximate to the bearing cartridge;

a second end cavity is partially defined by a second end of the shaft; and

the shaft includes a second shaft channel extending through the shaft to provide flow communication between the second end cavity and the second intermediary cavity.

10. A momentum exchange assembly, comprising:

an outer housing; and

an inner gimbal assembly disposed within the outer housing, the inner gimbal assembly including:

a stator housing;

a rotor assembly disposed at least partially within the stator housing, the rotor assembly including a shaft and an inertial element fixedly coupled to the shaft;

a spin bearing mounted to a first end of the shaft;

a bearing cartridge surrounding the spin bearing, the bearing cartridge having a first end and a second end; and

a spin motor disposed within the stator housing and around the shaft, the spin motor including a spin motor rotor and a spin motor stator, the spin motor rotor including an inner ring and an outer ring, the inner ring coupled to the shaft, the outer ring coupled to the inertial element, and the spin motor stator disposed in an annular gap between the inner ring and the outer ring and coupled to the stator housing,

wherein:

a first end cavity is partially defined by the first end of the bearing cartridge,

the shaft includes a first shaft channel extending through the shaft,

a first intermediary cavity is defined by a first portion of an outer surface of the spin motor and a first portion of a surface of the rotor assembly, and

the first shaft channel provides flow communication between the first end cavity and the first intermediary cavity.

11. The momentum exchange assembly of claim 10 , wherein:

the first end of the shaft is disposed proximate to the bearing cartridge;

a second end cavity is partially defined by a second end of the shaft; and

the shaft includes a second shaft channel extending through the shaft to provide flow communication between the second end cavity and the second intermediary cavity.

12. The momentum exchange assembly of claim 10 , wherein:

the shaft includes a plurality of shaft channels extending through the shaft;

a second intermediary cavity is defined by a second portion of the outer surface of the spin motor and a second portion of the surface of the rotor assembly; and

the plurality of shaft channels provides flow communication between the first end cavity and the second intermediary cavity.

13. The momentum exchange assembly of claim 12 , wherein the plurality of shaft channels are substantially evenly spaced around the shaft.

14. An inner gimbal assembly for use in a control moment gyroscope assembly and of the type that includes a stator housing and a spin motor disposed within the stator housing and on a shaft, the inner gimbal assembly comprising:

a first spin bearing mounted to the shaft; and

a bearing cartridge substantially surrounding the first spin bearing, the bearing cartridge having a first end partially defining a first end cavity, a second end partially defining a first intermediary cavity, and a bearing cartridge channel providing flow communication between the first end cavity and the first intermediary cavity,

wherein the inner gimbal assembly is disposed within an outer housing.

15. The inner gimbal assembly of claim 14 , wherein the bearing cartridge comprises a plurality of bearing cartridge channels extending from the first end of the bearing cartridge to the second end of the bearing cartridge.

16. The inner gimbal assembly of claim 14 , wherein

a second intermediary cavity is partially defined by the spin motor and the shaft; and

the shaft includes a first shaft channel providing flow communication between the first end cavity and the second intermediary cavity.

17. The inner gimbal assembly of claim 16 , wherein:

the shaft includes a second shaft channel providing flow communication between the second intermediary cavity and a second end cavity at least partially defined by an end of the shaft opposite the bearing cartridge.

18. The inner gimbal assembly of claim 14 , wherein:

a second intermediary cavity is partially defined by the spin motor and the shaft; and

the shaft includes a plurality of shaft channels providing flow communication between the first end cavity and the second intermediary cavity.

19. The inner gimbal assembly of claim 14 , further comprising:

a second spin bearing mounted to the shaft;

a diaphragm substantially surrounding the second spin bearing, the diaphragm having a diaphragm channel.

20. The inner gimbal assembly of claim 14 , further comprising:

a torque module assembly coupled to the inner gimbal assembly.